This invention relates to a rodless cylinder assembly, and more particularly, to a rodless cylinder assembly in which a piston is fitted in a cylinder barrel provided with an axial slit on the outer surface thereof from which a connecting part of the piston projects outwardly, and a slide mount is coupled to the connecting part while the axial slit is sealed by means of a seal band.
Japanese Patent Application Laid-Open (KOKAI) No. Sho-58-50302 published in 1983 discloses a rodless cylinder assembly of the type described above, in which a cylinder barrel is provided at both, i.e. opposite side walls with guide grooves of substantially V-shaped cross section and guide ridges of substantially V-shaped cross section are provided on a slide mount to be axially movable along the guide grooves in engagement therewith.
With the rodless cylinder assembly of the character disclosed in the said prior art publication, when a large load is applied to an upper surface of the slide mount, there is a fear of the opposite side walls of the cylinder barrel being deformed inwardly because of forcible pressing of the guide ridges against the lower oblique inner wall surfaces of the guide grooves. Moreover, when a lateral bending moment is applied to the slide mount, both the side walls of the cylinder barrel are inwardly deformed due to forcible pressing of one guide ridge against the upper oblique inner wall surface of one guide groove and forcible pressing of the other guide ridge against the lower oblique inner wall surface of the other guide groove, so that the axial slit of the cylinder barrel is narrowed and smooth displacement of the piston within the cylinder barrel becomes difficult. It will be noted that this provides a significant problem for the construction of a rodless cylinder of conventional type.